This project investigates the role of cerebral imaging in prognosis of stroke recovery by evaluating how blood flow and spectroscopic imaging methods can separate and quantify structural, vascular, and neuro-metabolic abnormalities post-stroke. This has potential significance to provide a rationale, based on physiological measurements, for patient management and rehabilitation stragegies, including the use of facilitatory versus compensatory rehabilitation techniques. The primary emphasis is on identifying the diaschisis component of reduced activity in the stroke penumbra, defined as a reductioin in regional neurometabolic activity outside the infarct not due to hemodynamic vascular constraints, and presumably due to deafferentation effects of the stroke. Since the amount of non-infarcted neural tissue identifies the amount of affected brain that has potential for recovery, it is hypothesized that volumetric quantitation of diaschisis will be highly correlated with stroke recovery prognosis. The diaschisis component will be identified by determining the volume of brain tissue with reduced blood flow that is in excess of the measured anatomic infarction size. This excessive volume (which is not due to ischemia) is presumed to be due to the reactive reduction of metabolism from diaschisis. Neuro-metabolic changes caused by combined diaschisis and ischemia will also be studied. T1 and T2 MRI will be conducted to determine the volume of braiin outside the infarction to anatomically localize the penumbra. A reference system method that permits accurate correlation of anatomic with functional imaging will be utilized.